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EP 1 789 151 B1 |
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EUROPEAN PATENT SPECIFICATION |
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Mention of the grant of the patent: |
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18.11.2009 Bulletin 2009/47 |
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Date of filing: 05.08.2005 |
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International Patent Classification (IPC):
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International application number: |
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PCT/GB2005/003093 |
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International publication number: |
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WO 2006/013386 (09.02.2006 Gazette 2006/06) |
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LINE MARKING APPARATUS
LINIENZIEHVORRICHTUNG
APPAREIL DE MARQUAGE DE LIGNE
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Designated Contracting States: |
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AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE
SI SK TR |
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Priority: |
06.08.2004 GB 0417517
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Date of publication of application: |
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30.05.2007 Bulletin 2007/22 |
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Proprietor: Fleet (Line Markers) Limited |
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Spring Lane South
Spring Lane Industrial Estate
Malvern, Worcestershire WR14 1AJ (GB) |
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Inventors: |
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- MCGUFFIE, Iain, Peter
Nr Bromyard Herefordshire (GB)
- NICHOLLS, Jeremy
Clitheroe Lancashire BB7 4EQ (GB)
- PHILPOTTS, Liam, Darren
Nr Leominster Herefordshire (GB)
- BALLARD, James Phillip
Malvern Worcestershire WR14 3PS (GB)
- DAVIS, Richard John
Malvern Worcestershire WR14 3PS (GB)
- SWATTON, Stewart Nathan Ridgley
Malvern Worcestershire WR14 3PS (GB)
- PALMER, Kevin James
Malvern Worcestershire WR14 3PS (GB)
- WALKER, Antony Willem
Malvern Worcestershire WE14 3PS (GB)
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Representative: Jackson, Derek Charles |
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Derek Jackson Associates
The Old Yard Lower Town
Claines
Worcestershire WR3 7RY Lower Town
Claines
Worcestershire WR3 7RY (GB) |
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References cited: :
EP-A- 1 022 542 GB-A- 2 386 969
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GB-A- 2 357 105
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Note: Within nine months from the publication of the mention of the grant of the European
patent, any person may give notice to the European Patent Office of opposition to
the European patent
granted. Notice of opposition shall be filed in a written reasoned statement. It shall
not be deemed to
have been filed until the opposition fee has been paid. (Art. 99(1) European Patent
Convention).
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[0001] This invention relates to line marking apparatus for example for marking lines on
sports fields and the like.
[0002] Line marking apparatus for sports fields is well known and generally comprises a
line marking head and a reservoir of line marking material mounted on a chassis provided
with wheels. The line marking apparatus may be pushed by a user or may be self-powered
with a seat and steering means for a user riding on the apparatus.
[0003] Although the user can steer the apparatus and guide the line marking head along a
generally straight line, it is not possible for the user, for example when marking
the edge of a football pitch, to maintain a substantially straight line over any significant
distance and small lateral deviations are inevitable. It is therefore desirable to
provide a line marking apparatus which is capable of marking a straight line even
if the user diverges from such line.
[0004] Lines are generally marked either by following a string which defines an edge of
the line to be marked (known as "stringing-out") or by overmarking an existing line.
Both stringing-out and overmarking require considerable skill on behalf of the user
to produce a straight line. In general, the faster the marking speed, the less straight
will be the resulting line. To produce a particularly straight line, a skilled user
is required to mark both carefully and slowly. It would clearly be advantageous to
be able to mark a straight line relatively quickly.
[0005] One of the straightness problems associated with stringing-out results from the possibility
that the string may move while the line is being marked. This may be due, for example,
to the machine or the user touching the string, by the string becoming lodged in grass
or the like, or even the effect of wind or the impact of the spray paint with which
the line is being marked.
[0006] Stringing-out can also give rise to spurious paint marks on the surface being marked
out. After a line has been marked, the string is generally covered with wet paint.
If the line is then moved to mark a further line, any contact of the wet paint on
the string with the surface being marked will give rise to spurious paint marks on
the surface being marked out. It would be advantageous to be able to eliminate spurious
paint marks.
[0007] It is known from
DE-A-4 013 950 to use a laser beam to guide a vehicle, such as a line marking apparatus, along a
straight line by adjusting the steering of the apparatus. Such a system is relatively
complex in that it is necessary to adjust the position of the entire vehicle in order
to adjust the position of the line marking head. That is, it is necessary to move
the entire vehicle which is relatively heavy, rather than only part of the vehicle,
and it is necessary to provide a mechanism which controls the steering of the vehicle.
Such a system would therefore require to be modified significantly in order to be
fitted to different types of line marking apparatus.
[0008] GB-A-2 386 969 describes an autonomous ground maintenance vehicle which is provided with marking
means comprising delivery means for applying a making material to the ground. Guidance
means is provided for guiding the ground maintenance vehicle and position sensing
means is provided for determining the position of the vehicle. The marking means is
controlled in response to the position of the vehicle according to the position sensor.
[0009] It is therefore an object of the present invention to provide a line marking apparatus
which overcomes or at least ameliorates the disadvantages set forth above.
[0010] According to the present invention there is provided a line marking apparatus comprising:
a chassis provided with wheels and with means for propelling the apparatus;
a line marking head adapted to dispense line marking material so as to mark a line
upon a surface over which the apparatus is moved;
means supporting the line marking head such that the line marking head is movable
laterally relative to the chassis; and
means for controlling lateral movement of the line marking head and including a detector
for detecting electromagnetic radiation and control means for moving the line marking
head in response to detection of the electromagnetic by the detector,
wherein the detector is movable with the line marking head and is adapted for detecting
a beam of electromagnetic radiation indicative of the line to be marked, whereby lateral
movement of the line marking head and of the detector relative to the chassis is controlled
such that the line marking head and the detector substantially follow the line to
be marked irrespective of whether the chassis deviates from the direction of such
line.
[0011] The apparatus may include a handle to facilitate pushing of the apparatus by a user.
Alternatively, the apparatus may include a motor for propelling the apparatus and
a seat for the user.
[0012] The supporting means may comprise an elongate housing incorporating means for moving
the line marking head laterally relative to the chassis. Line marking head support
means may extend from the elongate housing in a direction substantially parallel to
the line to be marked. Alternatively, an actuator shaft may extend laterally from
the elongate housing with the line marking head extending from the actuator shaft
in a direction substantially parallel to the line to be marked.
[0013] The apparatus may include means for indicating when the beam of electromagnetic radiation
is being detected by the detector. Such indicating means may comprise visual, audible
and/or tactile means. Alternatively or additionally, the apparatus may include means
for warning when the line marking head is approaching the limit of its lateral movement.
Such warning means may comprise visual, audible and/or tactile means.
[0014] The apparatus may include means for inhibiting the marking of a line in the event
the beam of electromagnetic radiation is not being detected by the detector.
[0015] The line marking head may be mounted pivotably such that the head can move upwardly
and downwardly to compensate for any unevenness in the surface being marked.
[0016] The line marking head may be mounted so as to extend from the chassis substantially
in the direction parallel to the line to be marked. Alternatively, the line marking
head may be mounted laterally of the chassis.
[0017] The detector may be provided with a shield for shielding the detector from unwanted
electromagnetic radiation.
[0018] The detector may be offset laterally relative to the line marking head.
[0019] The detector may be mounted substantially in an upright plane passing through dispensing
means of the line marking head. The detector may be mounted adjacent to the dispensing
means of the line marking head.
[0020] The detector may include a plurality of sensors. The sensors may be spaced apart
by a distance similar to the intended width of the beam of electromagnetic radiation.
Alternatively or additionally, the sensors may have differing spacings therebetween.
The sensors may have differing gains and/or differing sizes. For example, the relative
gains may increase from the innermost sensor(s) to the outermost sensors. A plurality
of rows of sensors may be provided.
[0021] For a better understanding of the present invention and to show more clearly how
it may be carried into effect reference will now be made, by way of example, to the
accompanying drawings in which:
Figure 1 is a schematic plan view of one embodiment of a line marking apparatus according
to the present invention;
Figure 2 is a schematic side elevational view of the line marking apparatus shown
in Figure 1; and
Figure 3 is a schematic view from the rear of another embodiment of a line marking
machine according to the present invention.
[0022] The figures show a line marking apparatus which comprises a body 2, which forms a
chassis, provided with four wheels 4 and a handle 6 to enable a user to propel the
apparatus. The body 2 is also provided with a reservoir for line marking material,
accessed by way of a removable closure 8, and with control equipment, accessed by
way of a removable closure 10, for supplying the line marking material to a line marking
head 12. Alternatively, a reservoir need not be provided in the body 2 and line marking
material, such as one or more tapes, may be dispensed from the line marking head.
Line marking apparatus incorporating such components is well known and requires no
further explanation.
[0023] Interposed between the line marking head 12 and the body 2 is a lateral adjustment
device 14. The lateral adjustment device 14 is securely fastened to the body 2, for
example in the region of opposite front corners of the body and includes an elongate
housing 16 incorporating a servo-motor (not shown) or other moving means provided
within one end thereof, which servo-motor, by way of a belt, chain or worm drive for
example, is adapted to move a supporting bar 18 laterally from side-to-side in response
to signals from control equipment provided in the body 2. The supporting bar 18 extends
forwardly from the body 2 generally in the direction of a line to be marked by the
apparatus. Although the elongate housing is shown as being mounted forwardly of the
body 2, other configurations are possible, such as the elongate housing being mounted
beneath the body 2.
[0024] As an alternative to the supporting bar extending directly forwardly of the elongate
housing, an actuator shaft may extend laterally from the elongate housing and may
be operated, for example, by hydraulic means, a rack and pinion assembly operated
by an electric motor, a lead-screw arrangement incorporating a rotatable threaded
rod and the line marking head 12 mounted on a body threaded onto the rod, or a simple
mechanical linkage such as a parallelogram linkage. The supporting bar then extends
forwardly from the free end of the actuator shaft. Such a configuration eliminates
the need for an elongate slot in the forward face of the elongate housing which could
be susceptible to the ingress of water, debris or the like. The actuator shaft can
readily be sealed to the housing by way of an annular seal of elastomeric material
which may expand and contract as the actuator shaft moves or which allows the actuator
shaft to move relative to the seal.
[0025] In order to minimise upward and downward flexing of the supporting bar 18 an upright
post 20 is provided a short distance from the elongate housing 16 and a reinforcing
flange 22; of generally triangular configuration, is secured to both the supporting
bar 18 and to the upright post 20, for example by welding.
[0026] A line marking head support 24 extends downwardly from the supporting bar 18 a short
distance from the elongate housing 16 and the line marking head 12 is mounted on the
support 24 by way of a pivot 26. A supply pipe 28 for the line marking material extends
upwardly from the line marking head 12 and passes through an aperture formed in the
supporting bar 18 in a manner which permits upward and downward movement of the line
marking head relative to the supporting bar so as to enable the line marking head
to compensate for unevenness of the ground over which the apparatus passes. The supply
pipe 28 is connected to the body 2 by way of a flexible hose 30 and thence to the
reservoir by conventional means (not shown).
[0027] Mounted on the supporting bar 18 is a detector 32. The detector 32 is electrically
connected to control equipment provided within the body 2 for controlling lateral
movement of the supporting bar 18 and consequently the line marking head 12. The detector
32 is mounted so as to be substantially in the same vertical plane as a line marking
material dispenser, such as a spray nozzle, forming part of the line marking head,
or at least in a plane which is close to the line marking material dispenser. In practice
the detector 32 is generally positioned immediately in front of the spray nozzle of
the line marking head 12. This has been found to be important in order to minimise
any yaw effects which can otherwise arise if the line marking head and the detector
are separated by a substantial distance in the direction of the line to be marked.
Similarly, it is desirable for the elongate housing to be as close to the body as
possible because the forward protrusion of the supporting bar 18 gives rise to an
exaggerated lateral movement of the supporting bar as compared with the front of the
body 2.
[0028] The lateral adjustment device, including the line marking head 12, may be removable
from the body 2 to facilitate transportation and/or storage of the line marking apparatus.
[0029] The detector 32 is adapted to be sensitive to a narrow beam of electromagnetic radiation,
for example a beam of laser energy, which extends along or parallel to the line to
be marked. Such a laser beam may be intensity modulated in order that the detector
sensitivity can be tuned only to detect radiation modulated at the modulation frequency
in order to eliminate interference due to incident radiation, such as sunlight. Alternatively,
pulse width modulation may be employed, which could be advantageous if communication
between the source and the line marking apparatus is required. Ideally, the beam of
electromagnetic radiation is vertically fanned, for example in the range 1 to 2 degrees,
to accommodate upward and downward movement of the detector due to undulations in
the ground surface. The beam of electromagnetic radiation may have a varying lateral
intensity profile, for example resembling a Gaussian distribution, rather than an
abrupt edge. The source of electromagnetic radiation may be the emitter itself or
may be a reflector of the original emitted radiation. Where a reflector is employed
it is possible to provide a plurality of reflectors over the area to be marked in
order to define a plurality of lines to be marked. In this respect, the use of a penta-prism
in conjunction with a laser source allows two lines to be marked at right angles to
each other without re-positioning the source of electromagnetic radiation. Other splitting
prisms are available which generate three or four separate beams, for example at 90
degree spacing. If desired, the detector 32 may be adjustable upwardly and downwardly
to compensate to the degree of irregularity in the surface to be marked. In order
to minimise any effects of stray electromagnetic radiation, the detector may be provided
with a shield which limits the ingress of stray radiation without diminishing the
response of the detector to direct radiation from the source. Alternatively or additionally,
the beam of electromagnetic radiation may be modulated in a predetermined manner and
the detector may be adapted to recognise only radiation having the predetermined modulation.
As a further alternative, the detector may incorporate a narrow-pass filter which
is adapted to pass substantially only the wavelength of emitted by the source of electromagnetic
radiation. If reflectors are used, these are preferably in the form of a narrow strip
of highly reflective material mounted upright on a base plate. Side plates may be
provided to shield the reflective material from sunlight.
[0030] The detector 32 tracks the beam of electromagnetic radiation and causes, by way of
control equipment provided in the body 2, the supporting bar 18 to move laterally
either left or right to maintain the supporting bar substantially in line with or
parallel to the beam of electromagnetic radiation. Thus, if the user should inadvertently
steer the apparatus to the left of the intended line to be marked, the detector 32
will cause the supporting bar 18 to move to the right by an appropriate amount to
maintain the supporting bar, and therefore the line marking head 12, substantially
in line with or parallel to the beam of electromagnetic radiation and consequently
along the line to be marked. Similarly, if the user should inadvertently steer the
apparatus to the right of the intended line to be marked, the detector 32 will cause
the supporting bar 18 to move to the left by an appropriate amount to maintain the
supporting bar, and therefore the line marking head 12, substantially in line or parallel
with the beam of electromagnetic radiation and consequently along the line to be marked.
Lateral movement of the supporting bar 18 in the elongate housing 16 therefore compensates
for any errors made by the user (within the bounds of the elongate housing) and maintains
a straight line irrespective of any such errors.
[0031] The detector 32 incorporates a plurality of sensors which are sufficient in number
(i.e., at least two) and spaced a sufficient distance apart such that the distance
separating the sensors is similar to the width of the beam of electromagnetic radiation
when the source is relatively close to the detector 32. In this way the beam of electromagnetic
radiation does not fall wholly between adjacent sensors, but rather at least one of
the sensors will receive electromagnetic radiation of substantially different intensity
to at least one of the other sensors when the source is at a substantial distance
from the detector 32 and the width of the beam may have increased somewhat. The spacing
between the sensors enables the control equipment to determine the location of the
detector relative to the axis of the beam and consequently to establish the amount
and direction of any movement of the supporting bar 18 that may be necessary to maintain
the supporting bar in line or parallel with the axis of the beam of electromagnetic
radiation. If desired, the sensors may be arranged in more than one, for example two,
laterally extending rows. The use of more than one row of sensors allows the control
equipment to determine whether the detector is substantially in a horizontal plane
or whether it, and therefore the line marking apparatus, is tilted, for example as
a result of marking a line on an uneven surface. Any such tilting could affect the
relative position of the line being marked and can be compensated for by the control
equipment moving the line marking head appropriately in order to maintain a straight
line.
[0032] While the beam of electromagnetic radiation will ideally be parallel this cannot
in practice be achieved and a small degree of divergence is inevitable. It has been
found that a lateral array of at least three, and ideally at least four, sensors spaced
a few millimeters apart allows the detector to function effectively with a wide range
of widths of the beam of electromagnetic radiation. The precise spacing of the sensors
can readily be determined by experiment and requires no inventive contribution.
[0033] Moreover, it is advantageous if the sensors have different gains. In this respect,
in the case of four sensors arranged in a lateral array the two inner sensors may
have a first gain and the two outer sensors may have a second gain, the second gain
being higher than the first gain. Ideally the gain of the two outer sensors is several
times the gain of the two inner sensors. If further sensors are provided in the lateral
array, the relative gains should increase from the innermost sensor(s) to the outermost
sensors. In this way the further the detector 32 is out of alignment with the beam
of electromagnetic radiation the greater is the feedback signal tending to move the
supporting bar 18 relative to the elongate housing 16 in order to align the detector
32 with the axis of the beam of electromagnetic radiation.
[0034] Additionally or alternatively, the dimensions of the sensors may differ. Thus, the
inner sensors may be relatively small and the outer sensors may be relatively large.
For example, the inner sensors may comprise photodiodes of about 0.1 mm
2 of relatively low sensitivity and spaced about 3 mm apart, while the outer sensors
may comprise photodiodes of about 7 mm
2 of relatively high sensitivity spaced about 40 mm apart. As explained hereinabove,
the precise spacings of the sensors will depend on the nature of the beam of electromagnetic
radiation emitted by the source and may require to be adapted. Where the beam of electromagnetic
radiation has a varying lateral intensity profile, the sensors can use the varying
intensity to generate a constantly varying feedback signal to the means for moving
the supporting bar 18 to control the position thereof. In this way, the inner sensors
respond more effectively when the line marking apparatus is relatively close to the
source of electromagnetic radiation, while the outer sensors respond mor effectively
when the line marking apparatus is relatively far from the source of electromagnetic
radiation.
[0035] The lateral adjustment device 14 may be adapted such that line marking may be carried
out both towards and away from the source of electromagnetic radiation. For example,
the detector sensors may be mounted in a transparent housing or the detector 32 may
be mounted in a manner which permits it to be moved through 180 degrees when the marking
direction is changed.
[0036] The control equipment in the body 2 may be adapted to respond to a situation in which
the beam of electromagnetic radiation is not being detected by the detector 32. If
the beam of electromagnetic radiation is not being detected the control equipment
may be adapted to discontinue the feed of line marking material to the line marking
head 12 in order that a line should not be marked in an incorrect location in the
event, for example, that the beam of electromagnetic radiation should be obstructed
or that the apparatus is moved by the user a sufficient distance away from the intended
line that movement of the supporting bar 18 in the elongate housing 16 is unable to
compensate. If desired, feed of the line marking material may only be discontinued
if the beam of electromagnetic radiation is not detected for a predetermined time,
such as 100 milliseconds. The incorporation of a delay reduces the risk of spurious
interruptions such as may be caused by a person or an animal passing the beam, while
ensuring that the line being marked does not visibly deviate from the desired line.
[0037] In order to eliminate as far as possible the possibility that movement of the supporting
bar 18 may be unable to compensate, the line marking apparatus may be provided with
a visual, audible and/or tactile warning means which warns the user when the supporting
bar 18 is approaching its maximum extent of movement within the elongate housing 16.
For example, visual warning means in the form of a row of light emitting diodes may
be provided to indicate the relative position of the head relative to the supporting
bar. The light emitting diodes may be of different colours, for example with green
LEDs in the region of the centre of the warning means, red LEDs at the end regions
of the warning means and orange LEDs intermediate the green and red LEDs. Such an
arrangement conveys to the operator the relative urgency of taking corrective action.
Similarly, the line marking apparatus may be provided with visual, audible and/or
tactile means to indicate to the user that the detector 32 is receiving the beam of
electromagnetic radiation.
[0038] In use of the line marking apparatus, the apparatus may be set up for marking a line
in a number of different ways. For example, a telescopic sighting means may be provided
on the source of electromagnetic radiation and directed at the line marking apparatus
or other target, either or both of which may be provided with a reflective element.
The target may be provided with indicating means, for example visual, audible or adapted
to transmit a signal, to indicate to the user that the source is correctly aimed.
[0039] Alternatively, the source may be provided with a target-seeking system. In such a
case, the target-seeking system will cause the source to rotate until it receives
information that the source is correctly aimed. The source is then locked in position.
Such a target-seeking system may include a detector mounted on the source and which
is responsive to radiation reflected back from the target or a detector mounted on
the target and which transmits a signal back to the target-seeking system by suitable
means, such as radio, infra-red or ultrasonic means. The signal may be either analog
or digital.
[0040] The target-seeking system may be controlled from the source, from the line marking
apparatus or from any other convenient location.
[0041] It will be appreciated that the line marking apparatus shown in the drawings is adapted
to be pushed by a user. However, the present invention is equally capable of being
employed in conjunction with a self-powered, or ride-on, line marking apparatus. In
contrast with controlling the steering of the line marking apparatus, it is relatively
straightforward to mount the lateral adjustment device on a variety of different line
marking apparatus. Further, although the lateral adjustment device is shown mounted
immediately in front of the line marking apparatus it may in certain circumstances,
for example when the apparatus is a ride-on apparatus or to provide a particularly
convenient configuration for manoeuvering around obstacles such as goal posts or the
like, be advantageous to mount the lateral adjustment device to one side of the line
marking apparatus. Such an arrangement is advantageous in that it eliminates or at
least minimises any deviation that may be required to manoeuver around an obstacle
positioned on or immediately adjacent to the line being marked. A further option is
to position the detector offset relative to the line marking head by a predetermined
distance and to position the source offset from the intended line by a similar distance
to further improve manoeuverability around obstacles. In this way the source is less
likely to be obscured by an obstacle. The offset should ideally be at least half the
width of any expected obstacle.
[0042] The line marking head 12 may be combined with a distance and/or position measuring
device to initiate or discontinue the supply of line marking material to mark a discontinuous
line or, because the line marking head 12 is movable laterally relative to the body
12, to make a mark in a lateral direction to the direction of the line being marked.
For example, on a football field lateral marks could be made indicating the correct
position of the centre line, goal area and the like. It would then not be necessary
to make separate measurements to mark the positions of such lines.
[0043] The distance and/or position measuring device may be a tape or cord adapted to allow
the user to determine the distance from a fixed point. For example, the tape or cord
may be provided with distance markings, which may be visual or otherwise encoded into
the tape or cord, such as by magnetic means. Alternatively, distance may be measured
by determining the number of rotations of a wheel provided as part of the line marking
apparatus. As a further alternative, distance may be determined in a manner well known
in optical rangefinders by analysing interference patterns in a modulated beam of
electromagnetic radiation.
[0044] In a more sophisticated arrangement, the supply of line marking material may be initiated
and discontinued to generate a pattern of marked and unmarked areas which can be marked
side-by-side as separate lines to build up an image on the surface being marked. If
desired, the line marking head may be provided with means for marking lines of different
colours which can be independently initiated and discontinued to build up a coloured
image on the surface being marked. Lines of relatively large width, or multiple adjacent
lines can be marked where the line marking head is expanded laterally to incorporate
means for marking multiple side-by-side lines.
[0045] As shown in Figure 3, the line marking head 12 and the detector 32 may be offset
laterally from the body 2 of the line marking apparatus. The supporting bar 18 is
not required in the embodiment of Figure 3. Such an arrangement allows the operator
a better view of the line being marked and allows the operator to walk directly behind
the line marking apparatus without having to straddle the line being marked in order
to avoid damaging the line. Moreover, the source of electromagnetic radiation may
be positioned behind the user without there being any risk of the user interrupting
the beam.
[0046] Thus, the detector may be adapted to detect radiation from a source of electromagnetic
radiation positioned in front of the apparatus or behind the apparatus. As a further
alternative, the detector may be turned through 180 degrees so as to be adaptable
to either position for the source of electromagnetic radiation. An ideal arrangement
for the source of electromagnetic radiation, especially in the case where the beam
is a laser beam, is behind the user so that the user is not looking towards the source
of laser radiation while marking a line. Such an arrangement can also save time in
that the user can set up the source of electromagnetic radiation and then mark the
line while walking away from the source, rather than setting up the source at the
far end of the line to be marked and subsequently having to walk the length of the
line to operate the line marking apparatus.
[0047] Because it is necessary only to move the line marking head 12 to align with the beam
of electromagnetic energy, there is relatively little mass to move. Consequently,
any corrections can be made relatively quickly, resulting in smaller line errors and
permitting an increased marking speed. It has been found that the lateral adjustment
device is sufficiently responsive that the line marking apparatus can be pushed at
running pace, or can travel at 15 to 25 kilometers per hour or more, while maintaining
a straight line to within about 2 to 3 mm. In contrast, we have found that it is possible
for an unskilled user to mark a line which is straight within ± 30 mm over a distance
of 120 metres without the use of any other means of guidance (such as strings or a
pre-marked line). This accuracy can be achieved at a fast walking pace if using a
pedestrian apparatus or at speeds in excess of 16 kilometers per hour if using a motorised
apparatus. Where the user is following a pre-marked line, the line can be re-marked
with even greater accuracy. Previously, this combination of speed and accuracy has
not been possible even when the line is marked by a skilled user.
[0048] It has also been found that, because only the line marking head requires to be moved
laterally, the line marking machine can accommodate the effects of any changes in
the direction in which the blades of grass are lying. The line marking apparatus moves
over and is supported by the grass, and the "lie" of the grass, that is the direction
in which the blades of grass are facing, can give rise to errors in the line being
marked. With conventional line marking machines, a change in the lie of the grass
can cause the machine, and therefore the line marking head, to move laterally by up
to 2 cm. This is an amount which is unacceptable for lines being marked on many sports
fields, for example. In a traditional line marking machine, in which the line marking
head is securely mounted on the chassis, any lateral movement is transferred directly
to the line marking head and gives rise to an error in the line being marked. By way
of contrast, in the case of the line marking apparatus according to the present invention,
because the line marking head is movable independently of the body, lateral errors
due to movement of the body as a result of changes in the lie of the grass are compensated
for by lateral movement of the line marking head relative to the body and such errors
in the line being marked do not arise.
1. A line marking apparatus
characterised by:
a chassis (2) provided with wheels (4) and with means (6) for propelling the apparatus;
a line marking head (12) adapted to dispense line marking material so as to mark a
line upon a surface over which the apparatus is moved;
means (14) supporting the line marking head such that the line marking head is movable
laterally relative to the chassis; and
means for controlling lateral movement of the line marking head and including a detector
(32) for detecting electromagnetic radiation and control means for moving the line
marking head in response to detection of the electromagnetic radiation by the detector,
characterised in that the detector (32) is movable with the line marking head (12) and is adapted for detecting
a beam of electromagnetic radiation indicative of the line to be marked, whereby lateral
movement of the line marking head and of the detector relative to the chassis is controlled
such that the line marking head and the detector substantially follow the line to
be marked irrespective of whether the chassis deviates from the direction of such
line.
2. An apparatus as claimed in claim 1, characterised in that the apparatus includes a handle (6) to facilitate pushing of the apparatus by a user.
3. An apparatus as claimed in claim 1, characterised in that the apparatus includes a motor for propelling the apparatus and a seat for the user.
4. An apparatus as claimed in any preceding claim,
characterised in that the supporting means (14) comprises an elongate housing (16) incorporating means
for moving the line marking head (12) laterally relative to the chassis (2).
5. An apparatus as claimed in claim 4, characterised in that line marking head support means (18) extends from the elongate housing (16) in a
direction substantially parallel to the line to be marked.
6. An apparatus as claimed in claim 4, characterised in that an actuator shaft extends laterally from the elongate housing (16) with the line
marking head (12) extending from the actuator shaft in a direction substantially parallel
to the line to be marked.
7. An apparatus as claimed in any preceding claim,
characterised in that the apparatus includes means for indicating when the beam of electromagnetic radiation
is being detected by the detector (32).
8. An apparatus as claimed in claim 7, characterised in that the indicating means is selected from visual, audible and/or tactile means.
9. An apparatus as claimed in any preceding claim,
characterised in that the apparatus includes means for warning when the line marking head (12) is approaching
the limit of its lateral movement.
10. An apparatus as claimed in claim 9, characterised in that the warning means is selected from visual, audible and/or tactile means.
11. An apparatus as claimed in any preceding claim,
characterised in that the apparatus includes means for inhibiting the marking of a line in the event the
beam of electromagnetic radiation is not being detected by the detector (32).
12. An apparatus as claimed in any preceding claim,
characterised in that the line marking head (12) is mounted pivotably such that the head can move upwardly
and downwardly to compensate for any unevenness in the surface being marked.
13. An apparatus as claimed in any preceding claim,
characterised in that the line marking head (12) is mounted so as to extend from the chassis (2) substantially
in the direction parallel to the line to be marked.
14. An apparatus as claimed in any one of claims 1 to 12,
characterised in that the line marking head (12) is mounted laterally of the chassis (2).
15. An apparatus as claimed in any preceding claim,
characterised in that the detector (32) is provided with a shield for shielding the detector from unwanted
electromagnetic radiation.
16. An apparatus as claimed in any preceding claim,
characterised in that the detector (32) is offset laterally relative to the line marking head (12).
17. An apparatus as claimed in any preceding claim,
characterised in that the detector (32) is mounted substantially in an upright plane passing through dispensing
means of the line marking head (12).
18. An apparatus as claimed in claim 17, characterised in that the detector (32) is mounted adjacent to the dispensing means of the line marking
head (12).
19. An apparatus as claimed in any preceding claim,
characterised in that the detector (32) includes a plurality of sensors.
20. An apparatus as claimed in claim 19, characterised in that the sensors are spaced apart by a distance similar to the intended width of the beam
of electromagnetic radiation.
21. An apparatus as claimed in claim 19 or 20,
characterised in that the sensors have differing spacings therebetween.
22. An apparatus as claimed in claim 19, 20 or 21,
characterised in that the sensors have differing gains and/or differing sizes.
23. An apparatus as claimed in claim 22, characterised in that the relative gains increase from the innermost sensor(s) to the outermost sensors.
24. An apparatus as claimed in any one of claims 19 to 23,
characterised in that a plurality of rows of sensors is provided.
1. Linienmarkierungsvorrichtung,
gekennzeichnet durch:
ein Fahrgestell (2), das mit Rädern (4) und einem Mittel (6) zum Antreiben der Vorrichtung
ausgestattet ist,
einen Linienmarkierungskopf (12) zum Spenden von Linienmarkierungsmaterial, um eine
Oberfläche, über die die Vorrichtung bewegt wird, mit einer Linie zu markieren,
ein Mittel (14), das den Linienmarkierungskopf so trägt, dass der Linienmarkierungskopf
relativ zum Fahrgestell seitlich bewegbar ist, und
ein Mittel zum Steuern der seitlichen Bewegung des Linienmarkierungskopfes, das einen
Detektor (32) zum Detektieren elektromagnetischer Strahlung und ein Steuermittel zum
Bewegen des Linienmarkierungskopfes als Reaktion auf die Detektion der elektromagnetischen
Strahlung durch den Detektor beinhaltet,
dadurch gekennzeichnet, dass der Detektor (32) mit dem Linienmarkierungskopf (12) bewegbar ist und die Aufgabe
hat, einen Strahl von elektromagnetischer Strahlung zu detektieren, der die Markierungslinie
anzeigt, wodurch die seitliche Bewegung des Linienmarkierungskopfes und des Detektors
relativ zum Fahrgestell so gesteuert wird, dass der Linienmarkierungskopf und der
Detektor im Wesentlichen der Markierungslinie folgen, unabhängig davon, ob das Fahrgestell
von der Richtung dieser Linie abweicht.
2. Vorrichtung nach Anspruch 1, dadurch gekennzeichnet, dass die Vorrichtung einen Griff (6) zum Erleichtern des Schiebens der Vorrichtung durch
einen Benutzer aufweist.
3. Vorrichtung nach Anspruch 1, dadurch gekennzeichnet, dass die Vorrichtung einen Motor zum Antreiben der Vorrichtung und einen Sitz für den
Benutzer beinhaltet.
4. Vorrichtung nach einem der vorherigen Ansprüche, dadurch gekennzeichnet, dass das Tragmittel (14) ein längliches Gehäuse (16) umfasst, das ein Mittel zum seitlichen
Bewegen des Linienmarkierungskopfes (12) relativ zum Fahrgestell (2) enthält.
5. Vorrichtung nach Anspruch 4, dadurch gekennzeichnet, dass sich das Linienmarkierungskopftragmittel (18) von dem länglichen Gehäuse (16) in
einer zu der Markierungslinie im Wesentlichen parallelen Richtung verläuft.
6. Vorrichtung nach Anspruch 4, dadurch gekennzeichnet, dass eine Aktuatorwelle seitlich von dem länglichen Gehäuse (16) ausgehend verläuft, wobei
der Linienmarkierungskopf (12) von der Aktuatorwelle in einer zur Markierungslinie
im Wesentlichen parallelen Richtung verläuft.
7. Vorrichtung nach einem der vorherigen Ansprüche, dadurch gekennzeichnet, dass die Vorrichtung ein Mittel zum Anzeigen beinhaltet, wenn der Strahl elektromagnetischer
Strahlung von dem Detektor (32) detektiert wird.
8. Vorrichtung nach Anspruch 7, dadurch gekennzeichnet, dass das Anzeigemittel aus einem visuellen, akustischen und/oder taktilen Mittel ausgewählt
ist.
9. Vorrichtung nach einem der vorherigen Ansprüche, dadurch gekennzeichnet, dass die Vorrichtung ein Mittel zum Warnen beinhaltet, wenn sich der Linienmarkierungskopf
(12) seiner seitlichen Weggrenze nähert.
10. Vorrichtung nach Anspruch 9, dadurch gekennzeichnet, dass das Warnmittel aus einem visuellen, akustischen und/oder taktilen Mittel ausgewählt
ist.
11. Vorrichtung nach einem der vorherigen Ansprüche, dadurch gekennzeichnet, dass die Vorrichtung ein Mittel beinhaltet, das das Aufbringen einer Markierungslinie
verhindert, falls der Strahl elektromagnetischer Strahlung vom Detektor (32) nicht
detektiert wird.
12. Vorrichtung nach einem der vorherigen Ansprüche, dadurch gekennzeichnet, dass der Linienmarkierungskopf (12) drehbar montiert ist, so dass sich der Kopf nach oben
und nach unten bewegen kann, um eventuelle Unebenheiten in der markierten Oberfläche
zu kompensieren.
13. Vorrichtung nach einem der vorherigen Ansprüche, dadurch gekennzeichnet, dass der Linienmarkierungskopf (12) so montiert ist, dass er vom Fahrgestell (2) in einer
zur Markierungslinie im Wesentlichen parallelen Richtung verläuft.
14. Vorrichtung nach einem der Ansprüche 1 bis 12, dadurch gekennzeichnet, dass der Linienmarkierungskopf (12) seitlich vom Fahrgestell (2) montiert ist.
15. Vorrichtung nach einem der vorherigen Ansprüche, dadurch gekennzeichnet, dass der Detektor (32) mit einem Schirm zum Abschirmen des Detektors vor unerwünschter
elektromagnetischer Strahlung ausgestattet ist.
16. Vorrichtung nach einem der vorherigen Ansprüche, dadurch gekennzeichnet, dass der Detektor (32) relativ zum Linienmarkierungskopf (12) seitlich versetzt ist.
17. Vorrichtung nach einem der vorherigen Ansprüche, dadurch gekennzeichnet, dass der Detektor (32) in einer im Wesentlichen aufrechten Ebene montiert ist, die durch
den Spender des Linienmarkierungskopfes (12) verläuft.
18. Vorrichtung nach Anspruch 17, dadurch gekennzeichnet, dass der Detektor (32) neben dem Spender des Linienmarkierungskopfes (12) montiert ist.
19. Vorrichtung nach einem der vorherigen Ansprüche, dadurch gekennzeichnet, dass der Detektor (32) mehrere Sensoren beinhaltet.
20. Vorrichtung nach Anspruch 19, dadurch gekennzeichnet, dass die Sensoren eine Distanz voneinander haben, die der beabsichtigten Breite des Strahls
der elektromagnetischen Strahlung ähnlich ist.
21. Vorrichtung nach Anspruch 19 oder 20, dadurch gekennzeichnet, dass die Sensoren unterschiedliche Abstände voneinander haben.
22. Vorrichtung nach Anspruch 19, 20 oder 21, dadurch gekennzeichnet, dass die Sensoren unterschiedliche Gewinne und/oder unterschiedliche Größen haben.
23. Vorrichtung nach Anspruch 22, dadurch gekennzeichnet, dass die relativen Gewinne von dem/den innersten Sensor(en) zu den äußersten Sensoren
zunehmen.
24. Vorrichtung nach einem der Ansprüche 19 bis 23, dadurch gekennzeichnet, dass mehrere Sensorenreihen vorgesehen ist.
1. Appareil de traçage de lignes
caractérisé par :
un châssis (2) pourvu de roues (4) et de moyens (6) de propulsion de l'appareil ;
une tête traceuse (12) adaptée pour distribuer un matériau de traçage de lignes de
sorte à tracer une ligne sur une surface au-dessus de laquelle l'appareil est déplacé
;
des moyens (14) qui supportent la tête traceuse de lignes de sorte que la tête traceuse
de lignes peut être déplacée latéralement relativement au châssis ; et
des moyens de commande du mouvement latéral de la tête traceuse de lignes, et qui
comprennent un détecteur (32) pour détecter un rayonnement électromagnétique et des
moyens de commande pour déplacer la tête traceuse de lignes en réponse à la détection
du rayonnement électromagnétique par le détecteur,
caractérisé en ce que le détecteur (32) peut être déplacé avec la tête traceuse de lignes (12) et est adapté
pour détecter un faisceau de rayons électromagnétiques indiquant la ligne à tracer
; le déplacement latéral de la tête traceuse de lignes et du détecteur relativement
au châssis est commandé de sorte que la tête traceuse de lignes et le détecteur suivent
sensiblement la ligne à tracer, que le châssis s'écarte ou non de la direction de
cette ligne.
2. Appareil selon la revendication 1, caractérisé en ce que l'appareil comprend un guidon (6) qui facilite la poussée de l'appareil par un utilisateur.
3. Appareil selon la revendication 1, caractérisé en ce que l'appareil comprend un moteur qui propulse l'appareil, ainsi qu'un siège pour l'utilisateur.
4. Appareil selon l'une quelconque des revendications précédentes, caractérisé en ce que les moyens de support (14) comprennent un carter allongé (16) qui incorpore des moyens
pour déplacer latéralement la tête traceuse de lignes (12) relativement au châssis
(2).
5. Appareil selon la revendication 4, caractérisé en ce que les moyens de support (18) de la tête traceuse de lignes s'étendent depuis le carter
allongé (16) dans une direction sensiblement parallèle à la ligne à tracer.
6. Appareil selon la revendication 4, caractérisé en ce qu'un arbre de commande s'étend latéralement à partir du carter allongé (16), la tête
traceuse de lignes (12) s'étendant depuis l'arbre de commande dans une direciton sensiblement
parallèle à la ligne à tracer.
7. Appareil selon l'une quelconque des revendications précédentes, caractérisé en ce que l'appareil comprend des moyens pour indiquer que le faisceau de rayons électromagnétiques
est en cours de détection par le détecteur (32).
8. Appareil selon la revendication 7, caractérisé en ce que les moyens indicateurs sont choisis parmi des moyens optiques, acoustiques et/ou
tactiles.
9. Appareil selon l'une quelconque des revendications précédentes, caractérisé en ce que l'appareil comprend des moyens qui émettent un avertissement lorsque la tête traceuse
de lignes se rapproche de la limite de son mouvement latéral.
10. Appareil selon la revendication 9, caractérisé en ce que les moyens avertisseurs sont choisis parmi des moyens optiques, acoustiques et/ou
tactiles.
11. Appareil selon l'une quelconque des revendications précédentes, caractérisé en ce que l'appareil comprend des moyens d'inhibition du traçage d'une ligne dans les cas où
ou le faisceau de rayons électromagnétiques n'est pas détecté par le détecteur (32).
12. Appareil selon l'une quelconque des revendications précédentes, caractérisé en ce que la tête traceuse de lignes (12) est montée de manière pivotante de sorte que la tête
peut se déplacer vers le haut et le bas pour compenser tout irrégularité éventuelle
de la surface en cours de marquage.
13. Appareil selon l'une quelconque des revendications précédentes, caractérisée en ce que la tête traceuse de lignes (12) est montée de sorte à faire saillie hors du châssis
(2), dans une direction sensiblement parallèle à la ligne à tracer.
14. Appareil selon l'une quelconque des revendications 1 à 12, caractérisé en ce que la tête traceuse de lignes (12) est montée latéralement relativement au châssis (2).
15. Appareil selon l'une quelconque des revendications précédentes, caractérisé en ce que le détecteur (32) est pourvu d'un blindage qui protège le détecteur contre les rayonnements
électromagnétiques indésirables.
16. Appareil selon l'une quelconque des revendications précédentes, caractérisé en ce que le détecteur (32) est décalé latéralement relativement à la tête traceuse de lignes.
17. Appareil selon l'une quelconque des revendications précédentes, caractérisé en ce que le détecteur (32) est monté dans un plan sensiblement vertical qui traverse les moyens
de distribution de la tête traceuse de lignes (12).
18. Appareil selon la revendication 17, caractérisé en ce que le détecteur (32) est monté adjacent aux moyens de distribution de la tête traceuse
de lignes (12).
19. Appareil selon l'une quelconque des revendications précédentes, caractérisé en ce que le détecteur (32) comprend une pluralité de capteurs.
20. Appareil selon la revendication 19, caractérisé en ce que les capteurs sont séparés par une distance semblable à la largeur prévue du faisceau
de rayons électromagnétiques.
21. Appareil selon la revendication 19 ou 20, caractérisé en ce que les capteurs sont séparés par des distances différentes.
22. Appareil selon la revendication 19, 20 ou 21, caractérisé en ce que les capteurs ont des gains différents et/ou des dimensions différentes.
23. Appareil selon la revendication 22, caractérisé en ce que les gains respectifs augmentent depuis le(s) capteurs intérieur(s) jusqu'aux capteurs
extérieurs.
24. Appareil selon l'une quelconque des revendications 19 à 23, caractérisé en ce qu'il est prévu une pluralité de rangées de capteurs.
REFERENCES CITED IN THE DESCRIPTION
This list of references cited by the applicant is for the reader's convenience only.
It does not form part of the European patent document. Even though great care has
been taken in compiling the references, errors or omissions cannot be excluded and
the EPO disclaims all liability in this regard.
Patent documents cited in the description